This is a great lowfat soup for the fall season. If you are unfamiliar with butternut squash, its more akin to pumpkin rather than other squashes (zucchini, yellow squash). This particular recipe serves mainly as a base for numerous variations. I often added roasted garlic pulp to the mixture before pureeing. Sometimes I add some brown sugar and nutmeg for a change. I also add heavy cream instead of sour cream when I am in the mood for a richer soup.